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Acute small bowel ischemia is a life-threatening condition with a high mortality rate due to its lack of specific symptoms and laboratory profile, which render difficulty in establishing early diagnosis. The etiology of acute small bowel ischemia includes occlusive forms (arterial embolism, arterial thrombosis, and venous thrombosis) and nonocclusive mesenteric ischemia, of which arterial causes are far more common than venous causes. CT, the mainstay of accurate diagnoses, allows the identification of the features of vascular abnormalities and intestinal ischemic injuries, and helps clinicians to restore intestinal blood flow. Without treatment, the prognosis for acute small bowel ischemia is poor. A high index of suspicion and familiarity with the CT spectral findings of bowel ischemia are required to ensure rapid recognition of this condition. [ABSTRACT FROM AUTHOR]

Artificial intelligence (AI) has revolutionized the medical diagnostic process of various diseases. Since the manual reading of capsule endoscopy videos is a time-intensive, error-prone process, computerized algorithms have been introduced to automate this process. Over the past decade, the evolution of convolutional neural network (CNN) enabled AI to detect multiple lesions simultaneously with increasing accuracy and sensitivity. Difficulty in validating CNN performance and unique characteristics of capsule endoscopy images make computer-aided reading systems in capsule endoscopy still on a preclinical level. Although AI technology can be used as an auxiliary second observer in capsule endoscopy, it is expected that in the near future, it will effectively reduce the reading time and ultimately become an independent, integrated reading system.

Objective To investigate the application value of magnetic resonance enterography(MRE) with multiple sequences indetection of small bowel diseases. Methods Thirty-four patients with suspected small bowel diseases received MR enterography.The patients underwent MRE with multiple sequences including breath-hold T2-weighted turbo spin-echo sequence(T2WI-TSE-BH)， diffusion weighted imaging(DWI)， Balanced steady-state free precession sequence(BTFE)，and enhanced 3D-THRIVE scans.The side effects were recorded and the image quality was graded as bad， good and excellent. Then we compared the results between MR enterography and surgery， pathology or clinic was performed．Results Plain scan sequences of COR- (T2WI-TSE -BH and DWI(b＝800) resulted in the best image quality. Diffusion sequence was of great value for assessing enteritis activity，and augmented sequences led to high-quality images to meet the requirements of clinical diagnosis. Conclusion MRE with multiple sequences with more information，high sensitivity and non-ionizing radiation，can be used as an important method in diagnosis of intestinal diseases. [ABSTRACT FROM AUTHOR]

Objective The objective was to show efficiency of magnetic resonance enterography (MRE) with our previously assessed new oral contrast agent. Materials and methods Each bowel segments was evaluated for luminal distension, wall conspicuity, wall thickening, and hyperintensity on fat-saturated (FS) T2-weighted and contrast enhancement on postcontrast FS T1-weighted images. Also, consensus scoring results of MRE exams were compared with the gold standard tests in terms of active inflammatory bowel disease detection. Results Sensitivity, specificity, accuracy, positive predictive value, and negative predictive value of MRE for active inflammatory bowel disease detection were 62%, 98%, 80%, 96%, and 71.4%, respectively. Conclusion MRE obtained with the new mixture has a high reliability and shows good correlation with endoscopic examination ± biopsy. [ABSTRACT FROM AUTHOR]

Background: Video capsule endoscopy (VCE) is an attractive method for diagnosing and objectively monitoring disease activity in celiac disease (CeD). Its use, facilitated by artificial intelligence- based tools, may allow computer-assisted interpretation of VCE studies, transforming a subjective test into a quantitative and reproducible measurement tool., Objective: To evaluate and compare objective CeD severity assessment as determined with VCE by expert human readers and a machine learning algorithm (MLA)., Methods: Patients ≥ 18 years with histologically proven CeD underwent VCE. Examination frames were scored by three readers from one center and the MLA, using a 4-point ordinal scale for assessing the severity of CeD enteropathy. After scoring, curves representing CeD severity across the entire small intestine (SI) and individual tertiles (proximal, mid, and distal) were fitted for each reader and the MLA. All comparisons used Krippendorff's alpha; values > 0.8 represent excellent to 'almost perfect' inter-reader agreement., Results: VCEs from 63 patients were scored. Readers demonstrated strong inter-reader agreement on celiac villous damage (alpha=0.924), and mean value reader curves showed similarly excellent agreement with MLA curves (alpha=0.935). Average reader and MLA curves were comparable for mean and maximum values for the first SI tertile (alphas=0.932 and 0.867, respectively) and the mean value over the entire SI (alpha=0.945)., Conclusion: A novel MLA demonstrated excellent agreement on whole SI imaging with three expert gastroenterologists. An ordinal scale permitted high inter-reader agreement, accurately and reliably replicated by the MLA. Interpreting VCEs using MLAs may allow automated diagnosis and disease burden assessment in CeD., (Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.net.)

Wireless video capsule endoscopy (VCE) is a minimally invasive technology that has revolutionized the approach to small intestinal disease investigation and management. Designed primarily to provide diagnostic imaging of the small intestine, VCE is used predominantly for obscure gastrointestinal bleeding and suspected Crohn's disease; however, numerous other indications have been established, including the assessment of celiac disease, investigation of small bowel tumors, and surveillance of hereditary polyposis syndromes. Since the introduction of small bowel VCE in 2000, more than 1600 articles have been published describing the evolution of this technology. The main adverse outcome is capsule retention, which can potentially be avoided by careful patient selection or by using a patency capsule. Despite the numerous advances in the past 15 years, limitations such as incomplete VCE studies, missed lesions, and time-consuming reporting remain. The inability to control capsule movement for the application of targeted therapy or the acquisition of tissue for histologic analysis remains among the greatest challenges in the further development of capsule technology. This article outlines the recent technological and clinical advances in VCE and the future directions of research in this field. [ABSTRACT FROM AUTHOR]

An increasing understanding of the pathogenesis of Crohn's disease (CD), coupled with improvements in therapeutic options, has promoted the concept of stratifying patients with CD into distinct disease phenotypes according to risk. Small bowel CD, due to the numerous non-specific potential symptoms and the anatomical location of the disease, is a particularly difficult phenotype to identify. The fact that the majority of de novo strictures occur in the ileum/ileo-colonic region ensures that recognition of small bowel involvement is essential. Certainly, it is becoming increasingly recognised due to improvements in imaging and endoscopic techniques. Both CT and MR enterography appear capable of accurately diagnosing small bowel CD. Furthermore, the development of capsule endoscopy and balloon-assisted enteroscopy allow direct visualisation of the small bowel. Limited data to date would suggest that small bowel CD is a difficult entity to treat even in the current era of the ever-expanding field of biological therapies. Further long-term follow-up studies are necessary using both small bowel capsule endoscopy and cross-sectional imaging to truly assess, firstly, whether small bowel CD is more resistant to treatment and, secondly, whether it has an effect over time in terms of complications. In the future, serological and genetic tests, coupled with the aforementioned investigations, will permit early diagnosis and early treatment of small bowel CD. © 2014 S. Karger AG, Basel [ABSTRACT FROM AUTHOR]

Crohn's disease is a chronic inflammatory bowel disease (IBD) that can affect the entire GI tract, and adequate visualization of the small bowel is imperative for both diagnosis and management. Magnetic resonance and computed tomography enterography have gradually replaced barium-based studies. Magnetic resonance enterography has the distinct advantage of avoiding ionizing radiation to which many patients with IBD are overexposed. Endoscopy-based techniques, including capsule endoscopy and device-assisted enteroscopy, allow direct visualization of the small bowel mucosa. Deep enteroscopy has the additional benefit of allowing sampling of the mucosa for histological analysis. Small intestine contrast ultrasound is rapidly gaining credence as an excellent, radiation-free imaging technique, but is not available in all countries. Other imaging modalities, such as positron emission tomography and leucocyte scintigraphy, continue to be studied and may have a role in specific circumstances. This review summarizes the evidence for the various techniques for evaluating the small bowel in IBD. [ABSTRACT FROM AUTHOR]

Background. Patients with Crohn's disease are often investigated using MRI enteroclysis which may provide better visual quality than MRI enterography, but exposes patients to radiation. Only few data exist of the radiation dose used in fluoroscopy prior to MRI enteroclysis. Subjects and methods. During the 12-month study period, all 95 patients (40 men) undergoing MRI enteroclysis with nasojejunal intubation using fluoroscopy for suspicion or evaluation of Crohn's disease were included. Average age at the time of MRI was 40.1 years (range 17-79). Conversion factors from dose-area product to effective dose were determined with a Monte Carlo-based software PCXMC. The conversion factors were determined for a standard-sized adult phantom for posterior-anterior and right-posterior-oblique projections. Results. The average total time of fluoroscopy was 3 min 17 s (range 0 min 7 s to 31 min). The average effective dose of ionizing radiation was 0.21 mSv (range 0.01-2.67). The average dose is equivalent to 10 PA chest x-rays. Standard deviation was 0.41 mSv. The highest effective dose of a single patient was 2.67 mSv. In comparison, a standard abdominal CT scan causes an effective dose of 12 mSv. Conclusions. The effective dose of ionizing radiation with nasojejunal intubation is relatively small in the majority of patients. When repeated imaging is necessary, it seems advisable to consider imaging techniques, which do not subject patients to ionizing radiation. Also if a previous nasojejunal intubation has been difficult, a different imaging technique is recommended. [ABSTRACT FROM AUTHOR]

Endoscopic investigation of small bowel pathology in children has historically been difficult due to location, length and tortuosity of the small bowel. Recently, video capsule endoscopy and balloon-assisted enteroscopy techniques have evolved as new diagnostic tools and are increasingly used in the paediatric population. In this review the current literature is appraised to define the clinical indications and practical aspects of capsule endoscopy and balloon-assisted enteroscopy in children. [Copyright &y& Elsevier]

Abstract: The small intestine has been difficult to examine by traditional endoscopic and radiologic techniques. Until the end of the last century, the small bowel follow through was the primary diagnostic tool for suspected small bowel disease. In recent years capsule endoscopy, deep enteroscopy using balloon-assisted or spiral techniques, computerized tomography and magnetic resonance enteroclysis or enterography have facilitated the diagnosis, monitoring, and management of patients with small bowel diseases. These technologies are complementary, each with its advantages and limitations. In the present article, we will discuss the different options and indications for modern diagnostic methods for visualization of the small bowel. We also try to provide a clinical rationale for the use of these different diagnostic options in less established, newly emerging, indications for small bowel evaluation. [Copyright &y& Elsevier]

The small intestine has been difficult to examine by traditional endoscopic and radiologic techniques. Within the past 10 years, advances have led to an explosion of technologies that facilitate examination of the entire small intestine. Wireless video capsule endoscopy, deep enteroscopy using balloon-assisted or spiral techniques, computer tomography (CT) and magnetic resonance (MR) enterography have facilitated the diagnosis, monitoring, and management of patients with small intestinal diseases. These technologies are complementary, each with its advantages and limitations. Capsule endoscopy provides a detailed view of the mucosal surface and has excellent patient acceptance, but does not allow therapeutics. Deep enteroscopy allows careful inspection of the mucosa and therapeutics, but is time consuming and invasive. Enterography (CT or MR) allows examination of the small bowel wall and surrounding structures. The initial best test for detecting small intestinal disease depends on clinical presentation and an astute differential diagnosis. [ABSTRACT FROM AUTHOR]

Objective: To assess the diagnostic accuracy of magnetic resonance imaging (MRI) in prospectively differentiating between fibrotic and active inflammatory small bowel stenosis in patients with Crohn's disease (CD). Materials and Methods: A total of 111 patients with histologically proven CD presenting with clinical and plain radiographic signs of small bowel obstruction underwent coronal and axial MRI scans after oral administration of polyethylene glycol solution. A stenosis was judged present if a small bowel segment had >80% lumen reduction as compared to an adjacent normal loop and mural thickening of >3 mm. At the level of the stenosis, both T2 signal intensity and post-gadolinium T1 enhancement were quantified using a 5-point scale (0: very low; 1: low; 2: moderate; 3: high; and 4: very high). A stenosis was considered fibrotic if the sum of the two values (activity score: AS) did not exceed 1. Results: A small bowel stenosis was identified in 48 out of 111 patients. Fibrosis was confirmed at histology in all of the 23 patients with AS of 0 or 1, who underwent surgery within 3 days of the MRI examination. In the remaining 25 patients (AS: 2-8), an active inflammatory stenosis was suspected and remission of the obstructive symptoms was obtained by means of medical treatment. One of these patients (AS: 2), however, underwent surgery after 14 days, due to recurrence. MRI had 95.8% sensitivity, 100% specificity, and 97.9% accuracy in the diagnosis of fibrotic stenosis. Conclusion: MRI is reliable in differentiating fibrotic from inflammatory small bowel stenosis in CD. [ABSTRACT FROM AUTHOR]

CT enterography has rapidly emerged as the preferred small bowel imaging modality at several tertiary care medical centers. It utilizes negative or neutral oral contrast agents to enhance small bowel mural assessments. A high sensitivity and specificity for active inflammation and its ability to detect extra-intestinal disease set CT enterography apart from more traditional imaging methods. It has also been shown to be of great value for the detection of occult penetrating disease, changing physician level of confidence, and altering management plans in a large proportion of patients. Concerns regarding radiation exposure will likely become less of an issue with new dose reduction techniques. CT enterography has begun to revolutionize Crohn's disease evaluations for luminal and extraluminal disease, and its role will likely continue to expand in diagnostic and management algorithms. Copyright © 2010 S. Karger AG, Basel [ABSTRACT FROM AUTHOR]

Crohn's disease is an idiopathic chronic intestinal illness that requires specialized medical care for prompt disease diagnosis and appropriate management. Clinicians must accurately interpret and integrate findings from multitude of sources in order to achieve diagnostic certainty. Ileocolonoscopy remains the most relied modality, allowing for a direct mucosal visualization and biopsies for histologic assessments. Serologic markers currently serve an adjunctive role, often utilized in attempts to further subtype patients with indeterminate colitis. Radiologic imaging, such as computed tomography enterography can evaluate the far reaches of the small intestine, while also providing information about penetrating complications and extraintestinal disease manifestations. Treatment options and strategies continue to evolve with new biologic agents and ongoing testing of aggressive "top-down" approaches. In addition, identification of increased colorectal cancer risks in individuals with Crohn's colitis has led to formal surveillance guidelines. The clinical diagnosis and management of Crohn's disease continues to be an area of rapid change and exciting developments. [ABSTRACT FROM AUTHOR]

The discrete shearlet transformation accurately represents the discontinuities and edges occurring in magnetic resonance imaging, providing an excellent option of a sparsifying transform. In the present paper, we examine the use of discrete shearlets over other sparsifying transforms in a low-rank plus sparse decomposition problem, denoted by L + S . The proposed algorithm is evaluated on simulated dynamic contrast enhanced (DCE) and small bowel data. For the small bowel, eight subjects were scanned; the sequence was run first on breath-holding and subsequently on free-breathing, without changing the anatomical position of the subject. The reconstruction performance of the proposed algorithm was evaluated against k-t FOCUSS. L + S decomposition, using discrete shearlets as sparsifying transforms, successfully separated the low-rank (background and periodic motion) from the sparse component (enhancement or bowel motility) for both DCE and small bowel data. Motion estimated from low-rank of DCE data is closer to ground truth deformations than motion estimated from L and S. Motility metrics derived from the S component of free-breathing data were not significantly different from the ones from breath-holding data up to four-fold undersampling, indicating that bowel (rapid/random) motility is isolated in S. Our work strongly supports the use of discrete shearlets as a sparsifying transform in a L + S decomposition for undersampled MR data. [ABSTRACT FROM AUTHOR]

The aim was to compare bowel distension and diagnostic properties of magnetic resonance imaging of the small bowel with oral contrast (MRI per OS) with magnetic resonance enteroclysis (MRE). Forty patients with suspected Crohn's disease (CD) were examined with both MRI methods. MRI per OS was performed with a 6% mannitol solution and MRE with nasojejunal intubation and a polyethylenglycol solution. MRI protocol consisted of balanced fast field echo (B-FFE), T2 and T1 sequences with and without gadolinium. Two experienced radiologists individually evaluated bowel distension and pathological findings including wall thickness (BWT), contrast enhancement (BWE), ulcer (BWU), stenosis (BWS) and edema (EDM). The diameter of the small bowel was smaller with MRI per OS than with MRE (difference jejunum: 0.55 cm, p < 0.001; ileum: 0.35 cm, p < 0.001, terminal ileum: 0.09 cm, p = 0.08). However, CD was diagnosed with high diagnostic accuracy (sensitivity, specificity, positive and negative predictive values: MRI per OS 88%, 89%, 89%, 89%; MRE 88%, 84%, 82%, 89%) and inter-observer agreement (MRI per OS k = 0.95; MRE k = 1). In conclusion, bowel distension was inferior in MRI per OS compared to MRE. However, both methods diagnosed CD with a high diagnostic accuracy and reproducibility. [ABSTRACT FROM AUTHOR]

The aim was to evaluate the importance of the osmolarity of different oral agents for bowel distension and the level of related adverse events. The longitudinal design included the exposition of different oral MR agents on two separate occasions. Four groups of volunteers were randomly given 350 ml gastrografin of three different concentrations and water. On the second occasion they received mannitol, iohexol or iodixanol with equivalent osmolarities, but the control group (water) received mannitol. We recorded the outcomes as the degree of bowel distension determined as the mean bowel section area and the total level of discomfort recorded from a visual analogue scale (VAS). The statistical analysis included scatter plots with the best-fitted line with linear regression to study the association between osmolarity and section area and the association between osmolarity and adverse events. A dose-response association was found between increasing osmolarity levels and bowel area in square centimeters (P = 0.00001). A similar dose-response association existed between increasing levels of osmolarity and adverse events (P = 0.001). Osmolarity appears to be more important for bowel distension than the physico-chemical characteristics of the nonabsorbable oral agents. The optimum osmolarity level is determined by the patient's tolerance of the adverse events. [ABSTRACT FROM AUTHOR]

Magnetic resonance enteroclysis (MRE) is an emerging technique for the evaluation of small bowel abnormalities. Adequate luminal distention, achieved by the administration of iso-osmotic water solution through a nasojejunal catheter, in combination with ultrafast sequences, such as single-shot turbo spin echo, true fast imaging with steady precession, half-Fourier acquired single-shot turbo spin echo, and 3D fast low-angle shot, results in excellent anatomic demonstration of the small bowel. Magnetic resonance fluoroscopy can be performed during MRE examination and might be useful in studying low-grade stenosis or motility-related disorders. Magnetic resonance enteroclysis is very promising in detecting the number and extent of involved small bowel segments in patients with Crohn's disease, and in disclosing lumen narrowing and extramural manifestations and complications of the disease. Initial experience shows that MRE is very efficient in the diagnosis of small bowel tumors and can be used in the evaluation of small bowel obstruction. [ABSTRACT FROM AUTHOR]

Artificial intelligence (AI) has revolutionized the medical diagnostic process of various diseases. Since the manual reading of capsule endoscopy videos is a time-intensive, error-prone process, computerized algorithms have been introduced to automate this process. Over the past decade, the evolution of convolutional neural network (CNN) enabled AI to detect multiple lesions simultaneously with increasing accuracy and sensitivity. Difficulty in validating CNN performance and unique characteristics of capsule endoscopy images make computer-aided reading systems in capsule endoscopy still on a preclinical level. Although AI technology can be used as an auxiliary second observer in capsule endoscopy, it is expected that in the near future, it will effectively reduce the reading time and ultimately become an independent, integrated reading system. [ABSTRACT FROM AUTHOR]

Computed tomography enterography (CTE) and magnetic resonance enterography (MRE) are presently state-of-the-art radiologic tests used to examine the small bowel for various indications. This article focuses on CTE and MRE for the evaluation of Crohn disease. The article describes recent efforts to achieve more standardized interpretation of CTE and MRE, summarizes recent research studies investigating the role and impact of CTE and MRE more directly for several different clinical and research issues beyond general diagnostic accuracy, and provides an update on progress in imaging techniques. Also addressed are areas that need further exploration in the future., (Copyright © 2018 Elsevier Inc. All rights reserved.)

The study of the small bowel (SB) has always been challenging both for clinicians and radiologist. It is a long and tortuous tube that can be affected by various pathologies whose signs and symptoms are usually non specific and can mimic other acute abdominal disorders. For these reasons, imaging plays a central role in the diagnosis of the different pathological conditions that can occur. They are important also in the management and follow up of chronic diseases. We expose and evaluate all the radiological methods that are now available for the study of the SB with particular emphasis on the technological improvement of cross-sectional imaging, such as computed tomography (CT) and magnetic resonance imaging (MRI). These techniques have, infact, highly improved in terms of execution times (fast acquisitions images), patients discomfort and radiation dose, for CT, with consequent reduced biological risks. Moreover, the new post-processing options with multiplanar reconstruction and isotropic images have made significant changes in the evaluation of the exams. Especially MRI scans have been improved by the advent of new sequences, such as diffusion weighted imaging and cine-MRI, parallel imaging and breath-hold sequences and can provide excellent soft-tissue contrast without the use of ionizing radiations.

Introduction Barium meal enteroclysis (BM) is the recommended imaging technique for small bowel inaccessable by ileocolonoscopy when diagnosing paediatric inflammatory bowel disease (IBD) (1). However it is subject to poor sensitivity and involves ionising radiation. MRI enterography (MRE) has recently been reported as an alternative methodology. We aimed to critically appraise the published evidence on use of MRE in diagnosis of paediatric IBD by systematic review. Methods Review of all English language data reporting MRE for the investigation of patients <16 years with known or suspected IBD. Searches of Medline (January 1950–November 2010) and Pubmed (January 1950–November 2010) were performed using keyword and MeSH terms; IBD; MRI; small bowel imaging. Reference lists of potential studies, handsearching and personal collections of authors were also examined. Two authors independently assessed the quality of studies for inclusion using the QUADAS tool (2). A third author was an arbiter in cases of disagreement. PWE-016 Results Database searches yielded 606 291 hits, combination word searches limited this to 968 titles. 38 studies were fully reviewed and 10 potential studies identified. 2 studies were excluded due to lack of separate paediatric data or inadequate methodological rigour. 8 studies were included (QUADAS scores 7–13/14) (table 1). Studies displayed heterogeneity in bowel preparation, scanning technique, reporting methodology and comparisons with BM, ultrasound and CT. Timing of ileocolonoscopy in relation to MRE was also variable. Two papers reported greater sensitivity and specificity for MRE in comparison to BM. Conclusion MRE is an sensitive and specific tool for the diagnosis of paediatric IBD. However technical considerations require refinement and standardisation, however MRE offers a significant reduction in ionising radiation exposure. Current data suggest that MRE should supercede BM as the small bowel imaging technique in centres with appropriate expertise. [ABSTRACT FROM PUBLISHER]

Introduction Multi-modal Flexible spectral Imaging Color Enhancement (FICE) (Fujinon, Saitama, Japan) is a novel imaging technique, which attempts to augment endoscopic detection and differentiation of gastrointestinal lesions. FICE is computer aided reprocessing that enhances original white light (WL) images by reconstituting virtual ones for a range of different optical wavelengths. Recently FICE has also been incorporated into reporting software of the most widely available small bowel capsule endoscopy (SBCE) system (GIVEN Imaging, Israel). This is the first study to evaluate the usefulness of FICE computer aided detection and differentiation of small bowel (SB) lesions seen at SBCE. Methods 30 WL video clips (10 seconds each), subdivided into six diagnostic categories (angioectasias, ulceration, polyps, coeliac disease, bleeding, normal) were selected from our SBCE database by an experienced capsule endoscopist. Each of these clips was then reprocessed to generate an additional four multi-modal FICE versions in different optical wavelengths (red, blue, green and enhanced contrast FICE). This generated a total 150 SBCE video clips (including original WL clips) that were evaluated by three experienced capsule endoscopists, blinded to the content of each clip. The primary endpoint was the assessment of high confidence interpretation of the correct diagnosis. Results Interim analysis of the results at this stage, suggest that the correct identification of the lesions appeared to be broadly similar for WL and all multimodal FICE wavelengths (84% for WL vs 89% for FICE). However, the confidence level of reporting appeared to be higher for WL than for FICE (84% vs 68%) at this stage. Intra-group analyses for FICE showed that the confidence level of reporting was highest for high contrast FICE and lowest for blue FICE (68% vs 45%). Conclusion The preliminary results suggest that although the diagnostic accuracy of FICE appears to be similar to that of WL, the confidence of reporting with FICE appears to be lower. This may be reflective of the novelty of the technology and therefore, minimal operator experience in its use. Further larger studies are required to evaluate any potential benefit of FICE over WL SB lesion detection and differentiation. [ABSTRACT FROM PUBLISHER]